Vigenère Cipher Implementation

The Vigenère cipher is a form of polyalphabetic substitution to encrypt alphabetic text by using a keyword. The Vigenère cipher is easy to understand and implement. It consists of several Caesar ciphers in sequence with different shift values.  

Euclid’s Algorithm to find GCD of two numbers

The Euclid’s algorithm (or Euclidean Algorithm) is a method for efficiently finding the greatest common divisor (GCD) of two numbers. The GCD of two integers X and Y is the largest number that divides both of X and Y (without leaving a remainder).  

Recursive Program to Calculate Factorial of a Number

Write a recursive C/C++ and java program to calculate factorial of a given positive number.   The factorial of a non-negative integer n is the product of all positive integers less than or equal to n. It is denoted by n!. There are n! different ways to arrange n distinct objects into a sequence.

Determine if a given string is palindrome or not

Write a program to determine if a given string is palindrome or not. A palindromic string is a string that remains the same when its characters are reversed. Like “ABCBA”, for example, it is “symmetrical”.